diff --git a/libs/gui/tests/SurfaceTextureClient_test.cpp b/libs/gui/tests/SurfaceTextureClient_test.cpp
index 25109f6cb..94b05bc2d 100644
--- a/libs/gui/tests/SurfaceTextureClient_test.cpp
+++ b/libs/gui/tests/SurfaceTextureClient_test.cpp
@@ -14,8 +14,9 @@
  * limitations under the License.
  */
 
-#include <gui/SurfaceTextureClient.h>
+#include <EGL/egl.h>
 #include <gtest/gtest.h>
+#include <gui/SurfaceTextureClient.h>
 
 namespace android {
 
@@ -57,4 +58,46 @@ TEST_F(SurfaceTextureClientTest, ConcreteTypeIsSurfaceTextureClient) {
     EXPECT_EQ(NATIVE_WINDOW_SURFACE_TEXTURE_CLIENT, result);
 }
 
+TEST_F(SurfaceTextureClientTest, ANativeWindowLockFails) {
+    sp<ANativeWindow> anw(mSTC);
+    ANativeWindow_Buffer buf;
+    ASSERT_EQ(BAD_VALUE, ANativeWindow_lock(anw.get(), &buf, NULL));
+}
+
+TEST_F(SurfaceTextureClientTest, EglCreateWindowSurfaceFails) {
+    sp<ANativeWindow> anw(mSTC);
+
+    EGLDisplay dpy = eglGetDisplay(EGL_DEFAULT_DISPLAY);
+    ASSERT_EQ(EGL_SUCCESS, eglGetError());
+    ASSERT_NE(EGL_NO_DISPLAY, dpy);
+
+    EGLint majorVersion;
+    EGLint minorVersion;
+    EXPECT_TRUE(eglInitialize(dpy, &majorVersion, &minorVersion));
+    ASSERT_EQ(EGL_SUCCESS, eglGetError());
+
+    EGLConfig myConfig = {0};
+    EGLint numConfigs = 0;
+    EGLint configAttribs[] = {
+        EGL_SURFACE_TYPE, EGL_WINDOW_BIT,
+        EGL_RENDERABLE_TYPE, EGL_OPENGL_ES2_BIT,
+        EGL_RED_SIZE, 8,
+        EGL_GREEN_SIZE, 8,
+        EGL_BLUE_SIZE, 8,
+        EGL_ALPHA_SIZE, 8,
+        EGL_DEPTH_SIZE, 16,
+        EGL_STENCIL_SIZE, 8,
+        EGL_NONE };
+    EXPECT_TRUE(eglChooseConfig(dpy, configAttribs, &myConfig, 1,
+            &numConfigs));
+    ASSERT_EQ(EGL_SUCCESS, eglGetError());
+
+    EGLSurface eglSurface = eglCreateWindowSurface(dpy, myConfig, anw.get(),
+            NULL);
+    ASSERT_EQ(EGL_NO_SURFACE, eglSurface);
+    ASSERT_EQ(EGL_BAD_NATIVE_WINDOW, eglGetError());
+
+    eglTerminate(dpy);
+}
+
 }
diff --git a/opengl/libs/EGL/egl.cpp b/opengl/libs/EGL/egl.cpp
index 3d5a4d16f..f4a16509e 100644
--- a/opengl/libs/EGL/egl.cpp
+++ b/opengl/libs/EGL/egl.cpp
@@ -1094,6 +1094,16 @@ EGLSurface eglCreateWindowSurface(  EGLDisplay dpy, EGLConfig config,
         EGLConfig iConfig = dp->configs[intptr_t(config)].config;
         EGLint format;
 
+        // for now fail if the window is not a Surface.
+        int type = -1;
+        ANativeWindow* anw = reinterpret_cast<ANativeWindow*>(window);
+        if ((anw->query(window, NATIVE_WINDOW_CONCRETE_TYPE, &type) != 0) ||
+                (type == NATIVE_WINDOW_SURFACE_TEXTURE_CLIENT)) {
+            LOGE("native window is a SurfaceTextureClient (currently "
+                    "unsupported)");
+            return setError(EGL_BAD_NATIVE_WINDOW, EGL_NO_SURFACE);
+        }
+
         // set the native window's buffers format to match this config
         if (cnx->egl.eglGetConfigAttrib(iDpy,
                 iConfig, EGL_NATIVE_VISUAL_ID, &format)) {